Matched Filter Detection of Seismicity in the Eastern Tennessee Seismic Zone around the 12 December 2018 M4.4 Dectaur, Tennessee Earthquake

Session: Seismicity and Tectonics of Stable Continental Interiors [Poster]
Type: Poster
Date: 4/30/2020
Time: 08:00 AM
Room: Ballroom
Description: 

Small to moderate-size earthquakes have occurred along the Eastern Tennessee Seismic Zone (ETSZ) for decades, resulting the second highest seismicity rate in Central and Eastern US (CEUS) following the New Madrid Seismic Zone. The current seismicity forms a nearly 250-km long diffuse zone, without clear lineation of fault structures. The most recent moderate-size earthquake (Mw 4.4) occurred on December 12, 2018 near Decatur, Tennessee and was widely felt in south-eastern US. However, it is still not clear what is the primary driving force of seismicity in this region. The most recent sequence provides an opportunity to improve understanding of spatio-temporal and statistical behavior in the ETSZ. The ANSS ComCat catalog lists two potential foreshocks in the week leading up to the Mw 4.4 mainshock, as well as about 23 aftershocks with magnitudes larger than 1.3 in the following month. These aftershocks show a diffuse E-W trend, roughly consistent with one of the nodal planes of the mainshock. However, high-frequency waveforms of nearby seismic recordings show possible missing events immediately following the mainshock. We are in the process of applying a matched filter approach to detect these missing earthquakes in this time period (12/5/2018 to 1/12/2018). In addition, we plan to relocate the newly detected seismicity, as well as determining the statistical properties of the sequence and mainshock source properties. Updated results will be presented at the meeting.

Presenting Author: Clara Daniels

Authors